Sam Querrey injures back, retires from Delray Beach Open

DELRAY BEACH, Fla. (AP) Sam Querrey, a semifinalist last week in Memphis, injured his back mid-match and retired from the Delray Beach Open while leading Alejandro Gonzalez of Colombia 6-3, 1-2 on Tuesday.

The sixth-seeded Querrey was serving at 30-40 when he bent low for a backhand volley, made the shot and then clutched his lower back. After attempting to stretch for a moment, Querrey asked for the trainer and left the court for treatment. After nearly nine minutes, the 27-year-old American, a semifinalist here in 2008, returned, shook his opponent's hand and conceded the match.

Two Americans advanced to the second round. Tim Smyczek beat 17-year-old wild card Stefan Kozlov 7-5, 6-2, while seventh-seeded Steve Johnson advanced when Mikhail Kukushkin of Kazakhstan retired because of illness while down 6-3, 4-1.